The oligometastatic spectrum in the era of improved detection and modern systemic therapy

99mTcPSMA-radioguided surgery in oligorecurrent prostate cancer: the randomised TRACE-II trial

OBJECTIVE

To investigate whether combination treatment of prostate-specific membrane antigen (PSMA)-based radioguided surgery (RGS) with short-term androgen deprivation therapy (ADT) improves oncological outcomes in men with oligorecurrent prostate cancer (PCa) as compared to treatment with short-term ADT only.

METHODS

The TRACE-II study is an investigator-initiated, prospective, randomised controlled clinical trial. Patients (aged >18 years) with hormone-sensitive recurrent PCa after radical prostatectomy or radiotherapy (brachytherapy or external beam radiotherapy), with involvement of ≤2 lymph nodes or local oligorecurrent disease within the pelvis as determined by PSMA positron emission tomography (PET)/computed tomography (CT) are randomly assigned in a 1:1 ratio between 6-month ADT (Arm A) or 6-month ADT plus RGS (Arm B). The primary objective is to determine clinical progression-free survival (CPFS) at 24 months. After PSMA-RGS, CPFS is defined as the time between the start of treatment and the appearance of a re-recurrence (any N1 or M1) as suggested by PSMA-PET/CT or symptoms related to progressive PCa, or death from any cause. The secondary objectives include metastasis-free survival at 2, 5 and 10 years, biochemical progression-free survival at 2 years, and patient-reported quality of life at 2, 5 and 10 years. A total of 60 patients, 30 per arm, will be included. The trial is powered (80%) to detect at least a 30% absolute difference in CPFS between the two study arms in the period 2 years after randomisation. We expect to enrol the required participants in 3 years. The study has an expected duration of 5 years in total.

CONCLUSIONS

Combining RGS with short-term ADT might be oncologically beneficial for patients with oligorecurrent PCa. In this first randomised controlled trial, we are investigating the potential oncological benefits of this combined treatment, while also focusing on maintaining quality of life.

Protocol for CHAMPION study: a prospective study of maximal-cytoreductive therapies for patients with de novo metastatic hormone-sensitive prostate cancer who achieve oligopersistent metastases during systemic treatment with apalutamide plus androgen deprivation therapy

BACKGROUND

The proposed trial is to examine the feasibility of prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT)-guided cytoreduction plus apalutamide and androgen deprivation therapy (ADT) for newly diagnosed metastatic hormone-sensitive prostate cancer (mHSPC) at oligometastatic state.

METHODS

CHAMPION (NCT05717582) is an open-label, single-arm, phase II trial, planning to enroll newly diagnosed mHSPC cases with oligometastases (≤ 10 distant metastatic sites in conventional imaging). Patients will receive 6 cycles of apalutamide plus ADT. Patients with oligometastatic disease at PSMA PET/CT after 3 treatment cycles will receive cytoreductive radical prostatectomy. PSMA PET/CT-guided metastasis-directed external radiation therapy will be determined by the investigators. Apalutamide plus ADT will be continued for 2 weeks postoperatively. The primary endpoint is the proportion of patients with undetectable prostate-specific antigen (PSA), no disease progression, and no symptom deterioration after 6 cycles of apalutamide plus ADT. Secondary endpoints include the percentage of patients with PSA ≤ 0.2 ng/mL and oligometastases by the end of 3 treatment cycles, PSA response rate, and safety. Fleming's two-stage group sequential design will be adopted in the study, where the null hypothesis is that the rate of patients with an undetectable PSA is ≤ 40% after 6 cycles of treatment, while the alternate hypothesis is an undetectable PSA of > 60%; with one-sided α = 0.05, power = 0.80, and an assumed dropout rate of 10%, the required number of patients for an effective analysis is 47. Enrolment in the study commenced in May 2023.

DISCUSSION

The multi-modal therapy based on treatment response may improve the prognosis of newly diagnosed mHSPC patients with oligometastases.

TRIAL REGISTRATION

The study is registered with Clinical Trials.Gov (NCT05717582). Registered on 8th February 2023.

Radiation therapy of the primary tumour and/or metastases of digestive metastatic cancers

Metastatic gastrointestinal cancer is not an uncommon situation, especially for pancreatic, gastric, and colorectal cancers. In this setting, few data are available on the impact of the treatment of the primary tumour. Oligometastatic disease is associated with longer survival in comparison with more advanced disease. Metastasis-directed therapy, such as stereotactic body radiotherapy, seems related to better outcomes, but the level of evidence is low. In most tumour locations, prospective data are very scarce and inclusion in ongoing trials is strongly recommended.

How Imaging Advances Are Defining the Future of Precision Radiation Therapy

Radiation therapy is fundamental in the treatment of cancer. Imaging has always played a central role in radiation oncology. Integrating imaging technology into irradiation devices has increased the precision and accuracy of dose delivery and decreased the toxic effects of the treatment. Although CT has become the standard imaging modality in radiation therapy, the development of recently introduced next-generation imaging techniques has improved diagnostic and therapeutic decision making in radiation oncology. Functional and molecular imaging techniques, as well as other advanced imaging modalities such as SPECT, yield information about the anatomic and biologic characteristics of tumors for the radiation therapy workflow. In clinical practice, they can be useful for characterizing tumor phenotypes, delineating volumes, planning treatment, determining patients' prognoses, predicting toxic effects, assessing responses to therapy, and detecting tumor relapse. Next-generation imaging can enable personalization of radiation therapy based on a greater understanding of tumor biologic factors. It can be used to map tumor characteristics, such as metabolic pathways, vascularity, cellular proliferation, and hypoxia, that are known to define tumor phenotype. It can also be used to consider tumor heterogeneity by highlighting areas at risk for radiation resistance for focused biologic dose escalation, which can impact the radiation planning process and patient outcomes. The authors review the possible contributions of next-generation imaging to the treatment of patients undergoing radiation therapy. In addition, the possible roles of radio(geno)mics in radiation therapy, the limitations of these techniques, and hurdles in introducing them into clinical practice are discussed. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

SBRT for Liver Tumors: What the Interventional Radiologist Needs to Know

This review summarizes the clinical evidence supporting the utilization of stereotactic body radiotherapy (SBRT) for liver tumors, including hepatocellular carcinoma, liver metastases, and cholangiocarcinoma. Emerging prospective evidence has demonstrated the benefit and low rates of toxicity across a broad range of clinical contexts. We provide an introduction for the interventional radiologist, with a discussion of underlying themes such as tumor dose-response, mitigation of liver toxicity, and the technical considerations relevant to performing liver SBRT. Ultimately, we recommend that SBRT should be routinely included in the armamentarium of locoregional therapies for liver malignancies, alongside those liver-directed therapies offered by interventional radiology.

Management of oligometastatic/metastatic sarcomas and place of local treatments with focus on modern radiotherapy approaches

Soft tissue sarcomas are a rare and heterogeneous disease. For localized disease, treatment is based on surgery and radiotherapy with or without chemotherapy depending on risk factors. Upfront metastases are present in 7 to 20% of cases, and are localized to the lungs in most of cases. Disseminated disease is generally considered incurable but in selected cases, aggressive local treatment of metastases allowed long survival. Treatment of primary tumour is often debated. Our purpose is to evaluate the literature concerning the role of radiotherapy in the management of primary metastatic soft tissue sarcomas.

RNA m6A methylation and MDSCs: Roles and therapeutic implications for radiotherapy

Emerging evidence suggests that local tumor radiotherapy reshapes the repertoire of circulating myeloid-derived suppressor cells (MDSCs) and leads to their infiltration into the tumor microenvironment, which poses a major obstacle for radiotherapy efficacy. Recent findings have identified RNA m6A modification at the nexus of both anti-tumor immunity and radiation response. Here, we examine the mechanisms by which this RNA modification modulates the immune milieu of the radiation-remodeled tumor microenvironment. We discuss potential therapeutic interventions targeting m6A machinery to improve radiotherapy response.

An Activatable Near-Infrared Fluorescent Probe for Precise Detection of the Pulmonary Metastatic Tumors: A Traditional Molecule Having a Stunning Turn

An accurate detection of lung metastasis is of great significance for making better treatment choices and improving cancer prognosis, but remains a big challenge in clinical practice. In this study, we propose a reinventing strategy to develop a pH-activatable near-infrared (NIR) fluorescent nanoprobe, pulmonary metastasis tracer (denoted as PMT), based on assembly of NIR dye IR780 and calcium phosphate (CaP). By delicately tuning the intermolecular interactions during the assembly process and dye doping content, as well as the synthetic condition of probe, the fluorescence of PMT could be finely adjusted via the tumor acidity-triggered disassembly. Notably, the selected PMT9 could sharply convert subtle pH variations into a distinct fluorescence signal to generate high fluorescence ON/OFF contrast, dramatically reducing the background signals. Benefiting from such preferable features, PMT9 is able to precisely identify not only the tumor sites in orthotopic lung cancer models but also the pulmonary metastases in mice with remarkable signal-to-background ratio (SBR). This study provides a unique strategy to turn shortcomings of traditional dye IR780 during in vivo imaging into advantages and further expand the application of fluorescent probe to image lung associated tumor lesions.

Risk factors of local control in adrenal metastases treated by stereotactic body radiation therapy - a systematic review and meta-analysis

Purpose

This study is aimed to explore risk factors affect the therapy outcomes of adrenal metastases (AM) for stereotactic body radiation therapy (SBRT) and guide clinical dose selection.

Methods and materials

PubMed, Embase and Web of Science were searched in September 22, 2022 in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines (PRISMA). Subgroup analysis and meta-regression were used to search for sources of heterogeneity and identify risky outcomes factors. Publication bias test and sensitivity analysis were also conducted.

Results

Thirty-three studies with full text from 2009 to 2022 about AM with SBRT on 1483 patients were included. Pooled 1- and 2-year local control (LC) and overall survival(OS) were 81.7% (95% confidence interval [CI], 75.6%-86.5%), 62.8% (95% CI, 53.8%-71.8%), 67.4% (95%CI, 61.8%-73.1%) and 46.5% (95%CI, 40.4%-52.6%), respectively. Biological effective dose (BED, α/β=10Gy) and dose per fraction affected 1-year LC (Qm=23.89, 15.10; P<0.0001, 0.0001). In the range of 60-80Gy (BED10), the group of dose per fraction ≥ 9Gy achieved the excellent 1-year LC (< 9Gy: ≥ 9Gy =78%, 91%; χ2 = 10.16, P = 0.001). Tracking technology significantly affected 1- and 2-year OS (Qm = 5.73, 8.75; P = 0.017, 0.003) and high tracking adoption group showed excellent 1- and 2- year OS (78.7% [95%CI, 68.6%- 88.9%]; and 62.9% [95%CI, 53.1%-72.7%]).

Conclusion

Increasing the dose per fraction appropriately may help control locally AM lesious. Tracking technology might contribute to improve survival of advanced patients with AM. But these results need prospective studies to verify them.

Decreased risk of radiation pneumonitis with concurrent use of renin-angiotensin system inhibitors in thoracic radiation therapy of lung cancer

Background

Radiation pneumonitis (RP) is the primary dose-limiting toxicity associated with radiotherapy. This study aimed to observe the effects of renin-angiotensin system inhibitors in Chinese patients with lung cancer who received thoracic radiation.

Methods

Patients with lung cancer who received thoracic radiation at a total dose of ≥45 Gray between October 2017 and December 2022 were enrolled in this study. We retrospectively evaluated the factors influencing grade 2 or higher RP.

Results

A total of 320 patients were enrolled in this study; 62 patients were identified as angiotensin receptor blockers or angiotensin-converting enzyme inhibitor users. Additionally, 99 patients (30.9%) had grade 2 or higher RP, and the incidence in the renin-angiotensin system inhibitor group was 17.7% (11 out of 62 patients). Patients in the renin-angiotensin system inhibitors (RASi) group were older and had a higher percentage of males, lower percentage of ECOG score 0, higher percentage of hypertension, and higher percentage of adenocarcinoma than those in the non-RASi group. ECOG score [hazard ratio (HR) = 1.69, p = 0.009], history of smoking (HR = 1.76, p = 0.049), mean dose (HR = 3.63, p = 0.01), and RASi (HR = 0.3, p = 0.003) were independent predictive factors for RP. All subgroups benefited from RASi.

Conclusion

This study showed that oral RASi administration has the potential to mitigate the incidence of grade 2 or higher RP in patients with lung cancer undergoing thoracic radiotherapy. To validate and further substantiate these findings, additional prospective research is warranted.

De Novo Metastatic Prostate Cancer: Are We Moving toward a Personalized Treatment?

De novo metastatic hormone-sensitive PC (mHSPC) accounts for 5-10% of all prostate cancer (PC) diagnoses but it is responsible for nearly 50% of PC-related deaths. Since 2015, the prognosis of mHSPC has slightly improved thanks to the introduction of new hormonal agents and chemotherapy combined with androgen deprivation therapy from the first-line setting. This review describes the current therapeutic opportunities for de novo mHSPC, focusing on potential molecular biomarkers identified in the main clinical trials that have modified the standard of care, the genomic features of de novo mHSPC, and the principal ongoing trials that are investigating new therapeutic approaches and the efficacy of a biomarker-guided treatment in this setting. The road toward personalized treatment for de novo mHSPC is still long, considering that the randomized clinical trials, which have furnished the basis of the current therapeutic options, stratified patients according to clinical criteria that did not necessarily reflect the biological rationale of the chosen therapy. The role of transcriptomic profiling of mHSPC as a predictive biomarker requires further validation, and it remains to be ascertained how the genomic variants detected in mHSPC, which are regarded as predictive in the castration-resistant disease, can be exploited in the mHSPC setting.

Combine radiotherapy and immunotherapy in esophageal squamous cell carcinoma

Immune checkpoint inhibitors(ICIs) have improved the survival of advanced esophageal squamous cell carcinoma (ESCC) patients. Radiotherapy is one of the common therapies to treat esophageal cancer. However, whether combination radiation therapy can increase the efficacy of immunotherapy is still up for debate. Radiotherapy combined with immunotherapy has proven to be a reliable and effective treatment for tumors, and it can work in combination with immunotherapy to achieve better anti-tumor effects. This review aims to discuss the efficacy and safety of combining radiotherapy and immunotherapy to treat ESCC by stages as well as the optimum radiotherapy dose and target volume, with a summary of clinical trials in ESCC.

Locoregional radiotherapy improves survival outcomes in de novo metastatic nasopharyngeal carcinoma treated with chemoimmunotherapy

BACKGROUND

We aimed to investigate the efficacy of locoregional radiotherapy (LRRT) in patients with de novo metastatic nasopharyngeal carcinoma (dmNPC) receiving chemotherapy combined with anti-programmed cell death receptor-1 monoclonal antibodies (anti-PD-1 mAbs) as first-line treatment and identify optimal candidates for LRRT.

MATERIALS AND METHODS

We enrolled patients with dmNPC receiving platinum-based palliative chemotherapy and anti-PD-1 mAbs followed or not followed by LRRT from four centers. The endpoints were progression-free survival (PFS), objective response rate (ORR), and overall survival (OS). We used the inverse probability of treatment weighting (IPTW) to balance the baseline characteristics of the LRRT and non-LRRT groups to minimize selection bias before comparative analyses. Multivariate analyses were carried out using the Cox proportional hazards model.

RESULTS

We included 163 patients with dmNPC (median follow-up: 22 months). The median PFS was 20 months, and the ORR was 92.0%; the median OS was not achieved. After IPTW adjustments, patients who received LRRT had a significant survival benefit over those not receiving LRRT (median PFS: 28 versus 15 months, P < 0.001). The Epstein-Barr virus DNA (EBV DNA) level after four to six cycles of anti-PD-1 mAbs [weighted hazard ratio (HR): 2.19, 95% confidence interval (CI) 1.22-3.92, P = 0.008] and LRRT (weighted HR: 0.58, 95% CI 0.34-0.99, P = 0.04) were independent prognostic factors. Patients with undetectable EBV DNA levels after four to six cycles of anti-PD-1 mAbs (early EBV DNA clearance) benefitted from LRRT (HR: 0.41, 95% CI 0.22-0.79, P = 0.008), whereas those with detectable levels did not (HR: 1.30, 95% CI 0.59-2.87, P = 0.51).

CONCLUSIONS

Palliative chemotherapy combined with anti-PD-1 mAbs followed by LRRT was associated with improved PFS in patients with dmNPC, especially for patients with early EBV DNA clearance.

Treatment of Oligometastatic Non-Small Cell Lung Cancer: An ASTRO/ESTRO Clinical Practice Guideline

PURPOSE

This joint guideline by American Society for Radiation Oncology (ASTRO) and the European Society for Radiotherapy and Oncology (ESTRO) was initiated to review evidence and provide recommendations regarding the use of local therapy in the management of extracranial oligometastatic non-small cell lung cancer (NSCLC). Local therapy is defined as the comprehensive treatment of all known cancer-primary tumor, regional nodal metastases, and metastases-with definitive intent.

METHODS

ASTRO and ESTRO convened a task force to address 5 key questions focused on the use of local (radiation, surgery, other ablative methods) and systemic therapy in the management of oligometastatic NSCLC. The questions address clinical scenarios for using local therapy, sequencing and timing when integrating local with systemic therapies, radiation techniques critical for oligometastatic disease targeting and treatment delivery, and the role of local therapy for oligoprogression or recurrent disease. Recommendations were based on a systematic literature review and created using ASTRO guidelines methodology.

RESULTS

Based on the lack of significant randomized phase 3 trials, a patient-centered, multidisciplinary approach was strongly recommended for all decision-making regarding potential treatment. Integration of definitive local therapy was only relevant if technically feasible and clinically safe to all disease sites, defined as 5 or fewer distinct sites. Conditional recommendations were given for definitive local therapies in synchronous, metachronous, oligopersistent, and oligoprogressive conditions for extracranial disease. Radiation and surgery were the only primary definitive local therapy modalities recommended for use in the management of patients with oligometastatic disease, with indications provided for choosing one over the other. Sequencing recommendations were provided for systemic and local therapy integration. Finally, multiple recommendations were provided for the optimal technical use of hypofractionated radiation or stereotactic body radiation therapy as definitive local therapy, including dose and fractionation.

CONCLUSIONS

Presently, data regarding clinical benefits of local therapy on overall and other survival outcomes is still sparse for oligometastatic NSCLC. However, with rapidly evolving data being generated supporting local therapy in oligometastatic NSCLC, this guideline attempted to frame recommendations as a function of the quality of data available to make decisions in a multidisciplinary approach incorporating patient goals and tolerances.

Integrated Clinical-Molecular Classification of Colorectal Liver Metastases: A Biomarker Analysis of the Phase 3 New EPOC Randomized Clinical Trial

Importance

Personalized treatment approaches for patients with oligometastatic colorectal liver metastases are critically needed. We previously defined 3 biologically distinct molecular subtypes of colorectal liver metastases: (1) canonical, (2) immune, and (3) stromal.

Objective

To independently validate these molecular subtypes in the phase 3 New EPOC randomized clinical trial.

Design, Setting, and Participants

This retrospective secondary analysis of the phase 3 New EPOC randomized clinical trial included a bi-institutional discovery cohort and multi-institutional validation cohort. The discovery cohort comprised patients who underwent hepatic resection for limited colorectal liver metastases (98% received perioperative chemotherapy) from May 31, 1994, to August 14, 2012. The validation cohort comprised patients who underwent hepatic resection for liver metastases with perioperative chemotherapy (fluorouracil, oxaliplatin, and irinotecan based) with or without cetuximab from February 26, 2007, to November 1, 2012. Data were analyzed from January 18 to December 10, 2021.

Interventions

Resected metastases underwent RNA sequencing and microRNA (miRNA) profiling in the discovery cohort and messenger RNA and miRNA profiling with microarray in the validation cohort.

Main Outcomes and Measures

A 31-feature (24 messenger RNAs and 7 miRNAs) neural network classifier was trained to predict molecular subtypes in the discovery cohort and applied to the validation cohort. Integrated clinical-molecular risk groups were designated based on molecular subtypes and the clinical risk score. The unique biological phenotype of each molecular subtype was validated using gene set enrichment analyses and immune deconvolution. The primary clinical end points were progression-free survival (PFS) and overall survival (OS).

Results

A total of 240 patients were included (mean [range] age, 63.0 [56.3-68.0] years; 151 [63%] male), with 93 in the discovery cohort and 147 in the validation cohort. In the validation cohort, 73 (50%), 28 (19%), and 46 (31%) patients were classified as having canonical, immune, and stromal metastases, respectively. The biological phenotype of each subtype was concordant with the discovery cohort. The immune subtype (best prognosis) demonstrated 5-year PFS of 43% (95% CI, 25%-60%; hazard ratio [HR], 0.37; 95% CI, 0.20-0.68) and OS of 63% (95% CI, 40%-79%; HR, 0.38; 95% CI, 0.17-0.86), which was statistically significantly higher than the canonical subtype (worst prognosis) at 14% (95% CI, 7%-23%) and 43% (95% CI, 32%-55%), respectively. Adding molecular subtypes to the clinical risk score improved prediction (the Gönen and Heller K for discrimination) from 0.55 (95% CI, 0.49-0.61) to 0.62 (95% CI, 0.57-0.67) for PFS and 0.59 (95% CI, 0.52-0.66) to 0.63 (95% CI, 0.56-0.70) for OS. The low-risk integrated group demonstrated 5-year PFS of 44% (95% CI, 20%-66%; HR, 0.38; 95% CI, 0.19-0.76) and OS of 78% (95% CI, 44%-93%; HR, 0.26; 95% CI, 0.08-0.84), superior to the high-risk group at 16% (95% CI, 10%-24%) and 43% (95% CI, 32%-52%), respectively.

Conclusions and Relevance

In this prognostic study, biologically derived colorectal liver metastasis molecular subtypes and integrated clinical-molecular risk groups were highly prognostic. This novel molecular classification warrants further study as a possible predictive biomarker for personalized systemic treatment for colorectal liver metastases.

Trial Registration

isrctn.org Identifier: ISRCTN22944367.

What is the ideal combination therapy in de novo, oligometastatic, castration-sensitive prostate cancer?

PURPOSE

To review current evidence regarding the management of de novo, oligometastatic, castration-sensitive prostate cancer (PCa).

METHODS

A literature search was conducted on PubMed/Medline and a narrative synthesis of the evidence was performed in August 2022.

RESULTS

Oligometastatic disease is an intermediate state between localized and aggressive metastatic PCa defined by ≤ 3-5 metastatic lesions, although this definition remains controversial. Conventional imaging has limited accuracy in detecting metastatic lesions, and the implementation of molecular imaging could pave the way for a more personalized treatment strategy. However, oncological data supporting this strategy are needed. Radiotherapy to the primary tumor should be considered standard treatment for oligometastatic PCa (omPCa). However, it remains to be seen whether local therapy still has an additional survival benefit in patients with de novo omPCa when treated with the most modern systemic therapy combinations. There is insufficient evidence to recommend cytoreductive radical prostatectomy as local therapy; or stereotactic body radiotherapy as metastasis-directed therapy in patients with omPCa. Current data support the use of intensified systemic therapy with androgen deprivation therapy (ADT) and next-generation hormone therapies (NHT) for patients with de novo omPCa. Docetaxel has not demonstrated benefit in low volume disease. There are insufficient data to support the use of triple therapy (i.e., ADT + NHT + Docetaxel) in low volume disease.

CONCLUSION

The present review discusses current data in de novo, omPCa regarding its definition, the increasing role of molecular imaging, the place of local and metastasis-directed therapies, and the intensification of systemic therapies.

Oligometastases: Characterizing the Role of Epigenetic Regulation of Epithelial-Mesenchymal Transition

The "oligometastasis" hypothesis proposes that metastases exist as a spectrum and are not always disseminated. According to this theory, a subset of patients with metastatic disease could benefit from aggressive local therapies. However, the identification of patients most likely to exhibit an oligometastatic phenotype remains challenging. Recent literature focusing on basic and translational studies has identified novel epigenetic regulators of epithelial-mesenchymal transition (EMT) and the emergence of a spectrum of metastatic behavior. Herein, we review these scientific advances and suggest that the spectrum of metastatic virulence produced by these epigenetic mechanisms broadly contributes to the emergence of clinically evident "oligometastases." Epigenetic regulation of EMT programs can result in a spectrum of cell trajectories (e.g., quasi-mesenchymal and highly mesenchymal states) with differential propensity to develop metastases. We propose that quasi-mesenchymal cell states may be associated with a polymetastatic phenotype, whereas highly mesenchymal cell states may be associated with a more oligometastatic phenotype. The mechanisms governing epigenetic regulation of EMT and its array of intermediate states are multifaceted and may contribute to the development of the metastatic spectrum observed clinically. Within this context, translational studies that support the role of EMT and its epigenetic regulation are discussed. Continued translation of these mechanistic discoveries into novel biomarkers may help optimally select patients most likely to exhibit an oligometastatic phenotype and benefit from aggressive local therapies, such as surgery, radiotherapy, and other ablative procedures.

A new paradigm for classifying and treating HER2-positive breast cancer

BACKGROUND

Because of the phenomenal success of treatment with monoclonal antibodies and antibody-drug conjugates targeting human epidermal growth factor receptor 2 (HER2), most patients with early-stage HER2-positive breast cancer (HER2+ BC) and some with limited metastatic diseases have been cured, and those who have not been cured have achieved significant improvements in overall survival, which has weakened the role of the TNM staging system in the prognosis of HER2+ BC today. Given that the disease is now highly curable, treatment conception, classification, and modalities should differ from those of cancer types with a poor prognosis. It is warranted to build a new paradigm for classifying and treating HER2+ BC.

RECENT FINDINGS

In our personal view, we suggest that the classification system should be based not only on traditional anatomy and cancer biology but also on available treatment regimens, their exceptional outcomes, and their toxicities. In this regard, we developed a new concise classification of HER2+ BC based on the TNM staging system, a review of the literature, research results, and our clinical experience, dividing the patients into four distinct groups: curable (lymph-node negative and small (≤3 cm) early breast cancer), do our best to cure (locally advanced or tumors >3 cm early breast cancer), hope for cure (local-regional recurrent, limited metastases, and exceptional responders), and incurable (metastatic breast cancer with poor performance status or non-exceptional responders).

CONCLUSION

It will assist clinicians in developing an optimal treatment regimen at the outset, curing more HER2+ BC patients and improving their quality of life.

Advanced gastric cancer achieving major pathologic regression after chemoimmunotherapy combined with hypofractionated radiotherapy: A case report

BACKGROUND

Currently, chemotherapy combined with immunotherapy is the established first-line standard treatment for advanced gastric cancer (GC). In addition, the combination of radiotherapy and immunotherapy is considered a promising treatment strategy.

CASE SUMMARY

In this report, we present a case of achieving nearly complete remission of highly advanced GC with comprehensive therapies. A 67-year-old male patient was referred to the hospital because he presented with dyspepsia and melena for several days. Based on fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT), endoscopic examination and abdominal CT, he was diagnosed with GC with a massive lesion and two distant metastatic lesions. The patient received mFOLFOX6 regimen chemotherapy, nivolumab and a short course of hypofractionated radiotherapy (4 Gy × 6 fractions) targeting the primary lesion. After the completion of these therapies, the tumor and the metastatic lesions showed a partial response. After having this case discussed by a multidisciplinary team, the patient underwent surgery, including total gastrectomy and D2 lymph node dissection. Postoperative pathology showed that major pathological regression of the primary lesion was achieved. Chemoimmunotherapy started four weeks after surgery, and examination was performed every three months. Since surgery, the patient has been stable and healthy with no evidence of recurrence.

CONCLUSION

The combination of radiotherapy and immunotherapy for GC is worthy of further exploration.

Advances in landscape and related therapeutic targets of the prostate tumor microenvironment

The distinct tumor microenvironment (TME) of prostate cancer (PCa), which promotes tumor proliferation and progression, consists of various stromal cells, immune cells, and a dense extracellular matrix (ECM). The understanding of the prostate TME extends to tertiary lymphoid structures (TLSs) and metastasis niches to provide a more concise comprehension of tumor metastasis. These constituents collectively structure the hallmarks of the pro-tumor TME, including immunosuppressive, acidic, and hypoxic niches, neuronal innervation, and metabolic rewiring. In combination with the knowledge of the tumor microenvironment and the advancement of emerging therapeutic technologies, several therapeutic strategies have been developed, and some of them have been tested in clinical trials. This review elaborates on PCa TME components, summarizes various TME-targeted therapies, and provides insights into PCa carcinogenesis, progression, and therapeutic strategies.

Addition of Metastasis-Directed Therapy to Intermittent Hormone Therapy for Oligometastatic Prostate Cancer: The EXTEND Phase 2 Randomized Clinical Trial

Importance

Despite evidence demonstrating an overall survival benefit with up-front hormone therapy in addition to established synergy between hormone therapy and radiation, the addition of metastasis-directed therapy (MDT) to hormone therapy for oligometastatic prostate cancer, to date, has not been evaluated in a randomized clinical trial.

Objective

To determine in men with oligometastatic prostate cancer whether the addition of MDT to intermittent hormone therapy improves oncologic outcomes and preserves time with eugonadal testosterone compared with intermittent hormone therapy alone.

Design, Setting, Participants

The External Beam Radiation to Eliminate Nominal Metastatic Disease (EXTEND) trial is a phase 2, basket randomized clinical trial for multiple solid tumors testing the addition of MDT to standard-of-care systemic therapy. Men aged 18 years or older with oligometastatic prostate cancer who had 5 or fewer metastases and were treated with hormone therapy for 2 or more months were enrolled to the prostate intermittent hormone therapy basket at multicenter tertiary cancer centers from September 2018 to November 2020. The cutoff date for the primary analysis was January 7, 2022.

Interventions

Patients were randomized 1:1 to MDT, consisting of definitive radiation therapy to all sites of disease and intermittent hormone therapy (combined therapy arm; n = 43) or to hormone therapy only (n = 44). A planned break in hormone therapy occurred 6 months after enrollment, after which hormone therapy was withheld until progression.

Main Outcomes and Measures

The primary end point was disease progression, defined as death or radiographic, clinical, or biochemical progression. A key predefined secondary end point was eugonadal progression-free survival (PFS), defined as the time from achieving a eugonadal testosterone level (≥150 ng/dL; to convert to nanomoles per liter, multiply by 0.0347) until progression. Exploratory measures included quality of life and systemic immune evaluation using flow cytometry and T-cell receptor sequencing.

Results

The study included 87 men (median age, 67 years [IQR, 63-72 years]). Median follow-up was 22.0 months (range, 11.6-39.2 months). Progression-free survival was improved in the combined therapy arm (median not reached) compared with the hormone therapy only arm (median, 15.8 months; 95% CI, 13.6-21.2 months) (hazard ratio, 0.25; 95% CI, 0.12-0.55; P < .001). Eugonadal PFS was also improved with MDT (median not reached) compared with the hormone therapy only (6.1 months; 95% CI, 3.7 months to not estimable) (hazard ratio, 0.32; 95% CI, 0.11-0.91; P = .03). Flow cytometry and T-cell receptor sequencing demonstrated increased markers of T-cell activation, proliferation, and clonal expansion limited to the combined therapy arm.

Conclusions and Relevance

In this randomized clinical trial, PFS and eugonadal PFS were significantly improved with combination treatment compared with hormone treatment only in men with oligometastatic prostate cancer. Combination of MDT with intermittent hormone therapy may allow for excellent disease control while facilitating prolonged eugonadal testosterone intervals.

Trial Registration

ClinicalTrials.gov Identifier: NCT03599765.

Optimal dosing regimen of CD73 blockade improves tumor response to radiotherapy through iCOS downregulation

BACKGROUND

Irradiation (IR) and immune checkpoint inhibitor (ICI) combination is a promising treatment modality. However, local and distance treatment failure and resistance can occur. To counteract this resistance, several studies propose CD73, an ectoenzyme, as a potential target to improve the antitumor efficiency of IR and ICI. Although CD73 targeting in combination with IR and ICI has shown attractive antitumor effects in preclinical models, the rationale for CD73 targeting based on CD73 tumor expression level deserves further investigations.

METHODS

Here we evaluated for the first time the efficacy of two administration regimens of CD73 neutralizing antibody (one dose vs four doses) in combination with IR according to the expression level of CD73 in two subcutaneous tumor models expressing different levels of CD73.

RESULTS

We showed that CD73 is weakly expressed by MC38 tumors even after IR, when compared with the TS/A model that highly expressed CD73. Treatment with four doses of anti-CD73 improved the TS/A tumor response to IR, while it was ineffective against the CD73 low-expressing MC38 tumors. Surprisingly, a single dose of anti-CD73 exerted a significant antitumor activity against MC38 tumors. On CD73 overexpression in MC38 cells, four doses of anti-CD73 were required to improve the efficacy of IR. Mechanistically, a correlation between a downregulation of iCOS expression in CD4⁺ T cells and an improved response to IR after anti-CD73 treatment was observed and iCOS targeting could restore an impaired benefit from anti-CD73 treatment.

CONCLUSIONS

These data emphasize the importance of the dosing regimen for anti-CD73 treatment to improve tumor response to IR and identify iCOS as part of the underlying molecular mechanisms. Our data suggest that the selection of appropriate dosing regimen is required to optimize the therapeutic efficacy of immunotherapy-radiotherapy combinations.

Metastatic Colorectal Cancer Patient with Microsatellite Stability and Germline BRAC2 Mutation Shows a Complete Response to Olaparib in Combination with a PD-1 Inhibitor and Bevacizumab: A Case Report and Review of the Literature

Metastatic colorectal cancer (mCRC) has a poor prognosis. Combining chemotherapy with targeted therapy constitutes a basic form of mCRC treatment. Immune checkpoint inhibitors have been recommended for microsatellite instability mCRC, while most patients harboring microsatellite stability (MSS) or proficient mismatch repair (pMMR) are less responsive to immunotherapy. Combinational targeted therapy, including poly-ADP ribose polymerase (PARP) inhibitors, has been considered a promising way to reverse immunotherapy resistance; however, there is no clear and consistent conclusions can be drawn from the current research. Here, we report the case of a 59-year-old woman diagnosed with stage IVB MSS mCRC who received three courses of capecitabine/oxaliplatin chemotherapy combined with bevacizumab as a first-line treatment, resulting in an overall evaluation of stable disease (-25.7%). However, the occurrence of adverse events of intolerable grade 3 diarrhea and vomiting forced the cessation of this therapy. A germline BRCA2 mutation was found by next-generation sequencing, and the patient further received a combination of olaparib, tislelizumab, and bevacizumab. This treatment regime resulted in a complete metabolic response and a partial response (-50.9%) after 3 months of treatment. Mild asymptomatic interstitial pneumonia and manageable hematologic toxicity were two adverse events associated with this combination therapy. This study provides new insights into the combination of PARP inhibitors and immunotherapy for MSS mCRC patients carrying germline BRCA2 mutations.

Emerging evidence and treatment paradigm of non-small cell lung cancer

Research on biomarker-driven therapy and immune check-point blockade in non-small cell lung cancer (NSCLC) is rapidly evolving. The width and depth of clinical trials have also dramatically improved in an unprecedented speed. The personalized treatment paradigm evolved every year. In this review, we summarize the promising agents that have shifted the treatment paradigm for NSCLC patients across all stages, including targeted therapy and immunotherapy using checkpoint inhibitors. Based on recent evidence, we propose treatment algorithms for NSCLC and propose several unsolved clinical issues, which are being explored in ongoing clinical trials. The results of these trials are likely to impact future clinical practice.

Metastasis

Most cancer-associated deaths occur due to metastasis, yet our understanding of metastasis as an evolving, heterogeneous, systemic disease and of how to effectively treat it is still emerging. Metastasis requires the acquisition of a succession of traits to disseminate, variably enter and exit dormancy, and colonize distant organs. The success of these events is driven by clonal selection, the potential of metastatic cells to dynamically transition into distinct states, and their ability to co-opt the immune environment. Here, we review the main principles of metastasis and highlight emerging opportunities to develop more effective therapies for metastatic cancer.

Clinical and pathological characterization of 158 consecutive and unselected oligometastatic breast cancers in a single institution

PURPOSE

Data about incidence, biological, and clinical characteristics of oligometastatic breast cancer (OMBC) are scarce. However, these data are essential in determining optimal treatment strategy. Gaining knowledge of these elements means observing and describing large, recent, and consecutive series of OMBC in their natural history.

METHODS

We collected data retrospectively at our institution from 998 consecutive patients diagnosed and treated with synchronous or metachronous metastatic breast cancer (MBC) between January 2014 and December 2018. The only criterion used to define OMBC was the presence of one to five metastases at diagnosis.

RESULTS

Of 998 MBC, 15.8% were classified OMBC. Among these, 88% had one to three metastases, and 86.7% had only one organ involved. Bone metastases were present in 52.5% of cases, 20.9% had progression to lymph nodes, 14.6% to the liver, 13.3% to the brain, 8.2% to the lungs, and 3.8% had other metastases. 55.7% had HR+/HER2- OMBC, 25.3% had HER2+OMBC, and 19% had HR-/HER2- OMBC. The HR+/HER2- subtype statistically correlated with bone metastases (p = 0.001), the HER2+subtype with brain lesions (p = 0.001), and the HR-/HER2- subtype with lymph node metastases (p = 0.008). Visceral metastases were not statistically associated with any OMBC subtypes (p = 0.186). OMBC-SBR grade III was proportionally higher than in the ESME series of 22,109 MBC (49.4% vs. 35.1%, p < 0.001).

CONCLUSION

OMBC is a heterogeneous entity whose incidence is higher than has commonly been published. Not an indolent disease, each subgroup, with its biological and anatomical characteristics, merits specific management.

Real-time administration of indocyanine green in combination with computer vision and artificial intelligence for the identification and delineation of colorectal liver metastases

Introduction

Fluorescence guided surgery for the identification of colorectal liver metastases (CRLM) can be better with low specificity and antecedent dosing impracticalities limiting indocyanine green (ICG) usefulness currently. We investigated the application of artificial intelligence methods (AIM) to demonstrate and characterise CLRMs based on dynamic signalling immediately following intraoperative ICG administration.

Methods

Twenty-five patients with liver surface lesions (24 CRLM and 1 benign cyst) undergoing open/laparoscopic/robotic procedures were studied. ICG (0.05 mg/kg) was administered with near-infrared recording of fluorescence perfusion. User-selected region-of-interest (ROI) perfusion profiles were generated, milestones relating to ICG inflow/outflow extracted and used to train a machine learning (ML) classifier. 2D heatmaps were constructed in a subset using AIM to depict whole screen imaging based on dynamic tissue-ICG interaction. Fluorescence appearances were also assessed microscopically (using H&E and fresh-frozen preparations) to provide tissue-level explainability of such methods.

Results

The ML algorithm correctly classified 97.2 % of CRLM ROIs (n = 132) and all benign lesion ROIs (n = 6) within 90-s of ICG administration following initial mathematical curve analysis identifying ICG inflow/outflow differentials between healthy liver and CRLMs. Time-fluorescence plots extracted for each pixel in 10 lesions enabled creation of 2D characterising heatmaps using flow parameters and through unsupervised ML. Microscopy confirmed statistically less CLRM fluorescence vs adjacent liver (mean ± std deviation signal/area 2.46 ± 9.56 vs 507.43 ± 160.82 respectively p < 0.001) with H&E diminishing ICG signal (n = 4).

Conclusion

ML accurately identifies CRLMs from surrounding liver tissue enabling representative 2D mapping of such lesions from their fluorescence perfusion patterns using AIM. This may assist in reducing positive margin rates at metastatectomy and in identifying unexpected/occult malignancies.

Stereotactic MR-Guided Radiotherapy for Liver Metastases: First Results of the Montpellier Prospective Registry Study

Liver stereotactic body radiotherapy (SBRT) is a local treatment that provides good local control and low toxicity. We present the first clinical results from our prospective registry of stereotactic MR-guided radiotherapy (MRgRT) for liver metastases. All patients treated for liver metastases were included in this prospective registry study. Stereotactic MRgRT indication was confirmed by multidisciplinary specialized tumor boards. The primary endpoints were acute and late toxicities. The secondary endpoints were survival outcomes (local control, overall survival (OS), disease-free survival, intrahepatic relapse-free survival). Twenty-six consecutive patients were treated for thirty-one liver metastases between October 2019 and April 2022. The median prescribed dose was 50 Gy (40-60) in 5 fractions. No severe acute MRgRT-related toxicity was noted. Acute and late gastrointestinal and liver toxicities were low and mostly unrelated to MRgRT. Only 5 lesions (16.1%) required daily adaptation because of the proximity of organs at risk (OAR). With a median follow-up time of 17.3 months since MRgRT completion, the median OS, 1-year OS and 2-year OS rates were 21.7 months, 83.1% (95% CI: 55.3-94.4%) and 41.6% (95% CI: 13.5-68.1%), respectively, from MRgRT completion. The local control at 6 months, 1 year and 2 years was 90.9% (95% CI: 68.3-97.7%). To our knowledge, we report the largest series of stereotactic MRgRT for liver metastases. The treatment was well-tolerated and achieved a high LC rate. Distant relapse remains a challenge in this population.

Ten-year experience of bone SBRT in breast cancer: analysis of predictive factors of effectiveness

PURPOSE

Data on the benefit of stereotactic body radiation therapy (SBRT) in patients with breast cancer (BC) and bone metastases remain limited. The purpose of this study is to report our 10-year experience of bone SBRT, analyzing toxicity and prognostic factors for local control (LC); progression-free survival, and overall survival (OS).

METHODS/PATIENTS

We analyzed all spine and non-spine bone SBRT performed in patients with BC during the 2012-2022 period at our institution. Treatments carried out with ablative intent in stereotactic conditions with dose/fraction ≥ 5 Gy in 5 or fewer sessions were considered. Demographic, treatment, and toxicity data were recorded according to CTCAEv4. Risk factors were assessed through univariate and multivariate analysis by Cox regression.

RESULTS

60 bone SBRT treatments were performed during the study period. 75% were spine SBRT and 25% were non-spine SBRT (median BED₄Gy was 80 Gy₄). The median age was 52.5 years (34-79). The median tumor volume was 2.9 cm³ (0.5-39.4). The median follow-up was 32.4 months (1.2-101.7). 1 and 2 years LC were 92.9 and 86.6%, respectively. 1 and 2 years OS were 100 and 90.6%, respectively. Multivariate analysis (MVA) associated volume of the treated lesion ≥ 13 cm³ with worse LC (p = 0.046; HR 12.1, 95%CI = 1.1-140.3). In addition, deferring SBRT > 3 months after lesion diagnosis to prioritize systemic treatment showed a significant benefit, improving the 2 years LC up to 96.8% vs. 67.5% for SBRT performed before this period (p = 0.031; HR 0.1, 95%CI = 0.01-0.8). Hormonal receptors, the total number of metastases, and CA15-3 value were significantly associated with OS in MVA. During follow-up, three non-spine fractures (5%) were observed.

CONCLUSIONS

According to our data, bone SBRT is a safe and effective technique for BC. Upfront systemic treatment before SBRT offers a benefit in LC. Therefore, SBRT should be considered after prior systemic treatment in this population.

Overall survival and cancer-specific survival were improved in local treatment of metastatic prostate cancer

Background

For metastatic prostate cancer (mPCa), radical prostatectomy (RP) and radiation therapy (RT) may improve overall survival (OS) and cancer-specific survival (CSS). Compared with RT, RP shows significant advantages in improving patient outcomes. External beam radiation therapy (EBRT) even slightly elevates CSM with no statistical difference in OS compared with no local treatment (NLT).

Objective

To evaluate OS and CSS after local treatment (LT) (including RP and RT) versus NLT in mPCa. Design, setting, and participants Within the Surveillance, Epidemiology and End Results (SEER) database (2000-2018), 20098 patients with metastatic prostate cancer were selected in this study, of which 19433 patients had no local treatment, 377 patients with radical prostate treatment, and 288 patients with RT.

Outcome measurements and statistical analysis

Multivariable competing risks regression analysis after propensity score matching (PSM) was used to calculate CSM. Multivariable Cox regression analysis was used to identify the risk factors. Kaplan-Meier methods were used to calculate OS.

Results and limitations

A total of 20098 patients were included: NLT (n = 19433), RP (n=377) and RT (n=288). In a competing risk regression analysis after PSM (ratio 1:1), RP resulted in a significantly lower CSM (hazard ratio [HR] 0.36, 95% confidence interval [CI] 0.29-0.45) than NLT, while RT showed a slightly lower CSM (HR 0.77, 95% CI 0.63-0.95). In a competing risk regression analysis after PSM (ratio 1:1), RP led to a lower CSM (HR 0.56, 95% CI 0.41-0.76) versus RT. As for all-cause mortality (ACM), RP (HR 0.37, 95% CI 0.31-0.45) and RT (HR 0.66, 95% CI 0.56-0.79). also showed a downward trend. In terms of OS, RP and RT significantly improved the survival probability compared with NLT, with the effect of RP being more pronounced. Obviously, older age, Gleason scores ≥8, AJCC T3-T4 stage, AJCC N1, AJCC M1b-M1c were all associated with higher CSM (P <0.05). The same results held true for ACM. The limitation of this article is that it is not possible to assess the effect of differences in systemic therapy on CSM in mPCa patients and clinical trials are needed to verify the results.

Conclusions

For patients with mPCa, both RP and RT are beneficial to patients, and the efficacy of RP is better than RT from the perspective of CSM and ACM. Older age, higher gleason scores and the more advanced AJCC TNM stage all put patients at higher risk of dying.

Patient summary

A large population-based cancer database showed that in addition to first-line therapy (hormonal treatment), RP and radiotherapy can also benefit patients with mPCa.

The current role of precision surgery in oligometastatic prostate cancer

Oligometastatic prostate cancer (omPCa) is a novel intermediate disease state characterized by a limited volume of metastatic cells and specific locations. Accurate staging is paramount to unmask oligometastatic disease, as provided by prostate-specific membrane antigen-positron emission tomography. Driven by the results of prospective trials employing conventional and/or modern staging modalities, the treatment landscape of omPCa has rapidly evolved over the last years. Several treatment-related questions comprising the concept of precision strikes are under development. For example, beyond systemic therapy, cohort studies have found that cytoreductive radical prostatectomy (CRP) can confer a survival benefit in select patients with omPCa. More importantly, CRP has been consistently shown to improve long-term local symptoms when the tumor progresses across disease states due to resistance to systemic therapies. Metastasis-directed treatments have also emerged as a promising treatment option due to the visibility of oligometastatic disease and new technologies as well as treatment strategies to target the novel PCa colonies. Whether metastases are present at primary cancer diagnosis or detected upon biochemical recurrence after treatment with curative intent, targeted yet decisive elimination of disseminated tumor cell hotspots is thought to improve survival outcomes. One such strategy is salvage lymph node dissection in oligorecurrent PCa which can alter the natural history of progressive PCa. In this review, we will highlight how refinements in modern staging modalities change the classification and treatment of (oligo-)metastatic PCa. Further, we will also discuss the current role and future directions of precision surgery in omPCa.

Oligometastatic breast cancer: Dissecting the clinical and biological uniqueness of this emerging entity. Can we pursue curability?

Metastatic breast cancer represents an incurable condition, however, the increasing interest towards the oligometastatic entity is now challenging this assumption. Up to 20% of patients with metastatic breast cancer present with oligometastatic disease, which refers to metastatic breast cancer presenting or recurring with limited metastatic burden. In the last years, progressive advancements in imaging techniques, the growing availability of minimally invasive locoregional treatments, alongside the increasing expectations from a patient perspective, have contributed to rising the awareness towards this emerging entity. In the present work we comprehensively reviewed available evidence regarding oligometastatic breast cancer, focusing on clinical and biological notions virtually supporting the adoption of a curative approach when treating this condition. We also discussed main areas of uncertainties, providing a research agenda that may guide and fine-tune the future investigation in this field.